[RickM]

As inspired by the "Most disgusting practical joke" thread, tell us about your best.

Here's one of mine:

In 6th grade I hollowed out a book and wired in a step-up transformer, microswitch and battery. I covered the book with very thin metal sheet (Cartographer plate) and in my best hand printing wrote "1001 Dirty Jokes" (perfect title for Catholic school in the early seventies). I'm surprised I didn't stop some kid's heart cause this thing was powerful....and hilarious.